package com.itxiaowu.utils;

import java.util.Random;

/**
 *  随机生成验证码工具
 */
public class ValidateCodeUtils
{

    /**
     * 随机生成验证码
     */
    public static Integer generateValidateCode(int length){
        Integer code = null;

        if(length == 4){
            code = new Random().nextInt(9999); //生成随机数，最大为9999
            if(code < 1000){
                code += 1000;  // 保证随机数为4位数
            }
        }else if(length == 6){
            code = new Random().nextInt(999999); // 生成随机数，最大为999999
            if(code < 100000){
                code += 100000;  //保证随机数为6为数字
            }
        }else{
            throw new RuntimeException("只能生成4位或6位数字验证码");
        }
        return code;
    }

    /**
     *  随机生成指定长度字符串验证码
     */
    public static String generateValidateCode4String(int length){

        Random rdm = new Random();
        String hash1 = Integer.toHexString(rdm.nextInt());
        String capstr = hash1.substring(0,length);
        return capstr;

    }

    public static void main(String[] args) {
        String s = String.valueOf(generateValidateCode(4));
        System.out.println(s);
    }

}
